IBS and lactose intolerance both cause symptoms of diarrhea, abdominal pain, and bloating. Diagnoses of both IBS and lactose intolerance are made with a health history and without invasive tests.

Lactose intolerance is usually diagnosed based on symptoms, but a healthcare provider can also perform breath and blood testing. Breath tests are also available as over-the-counter home test kits.

Lactose intolerance is a common condition that often has a genetic component that can be inherited. Other cases may result from injuries, medications, or chronic medical conditions. Lactose ...